Since the advent of telephone communications, callers have frequently failed to make contact with the person they are calling either because that person is on another line, away from the phone, or otherwise preoccupied. Time and effort are wasted by playing telephone tag. This problem is especially acute in the business environment as customers are faced with unanswered calls, extended waits on hold, unconveyed important information, etc. Communication within an organization between employees is also a problem because of availability at the same time of the people who need to communicate. Time zone differences, especially in regards to international calls, particularly aggravate this issue.
Traditionally, a caller who cannot get hold of the person they are trying to contact could leave a message with a receptionist or secretary. However, written messages are notoriously prone to inaccuracies and are practically limited in length. Furthermore, this approach only works during business hours when the receptionist or secretary is available to pick up the incoming call.
In response to the shortcomings of handwritten messaging, electronic voice and text messaging systems have been developed. A number of voice and text messaging systems are known in the art and are commercially available. A voice messaging system is used to automate the answering of incoming calls from the outside telephone network and the taking of messages when the extensions are not answered by the called parties. Voice message systems are also used for people using any standard DTMF (Dual Tone Multi-Frequency) phone to call the voice message system and create messages that are then addressed and sent to one or more select other users of the system. Such voice messaging systems incorporate features, such as the recording of voice messages for users in what are known as "mailboxes". Commonly, voice messaging systems may also be accessed by users calling from PBX extensions or from the telephone network over incoming trunks to access their mailbox to listen to voice messages.
In most known voice messaging systems, answering of incoming trunk calls by the voice messaging system is accomplished by instructing the PBX to direct the incoming calls to a group of extensions. Voice ports of the voice messaging system are coupled with this group of extensions and appear to the PBX simply as single line telephone sets in a hunt group. Typically, the voice messaging system will answer a call directed to it and provide a pre-recorded voice message allowing the caller to "log-on" (i.e., enter a user identification number and security code) to access their mailbox in order to listen to or send voice messages. Internal users on the PBX can directly call the group of extensions in the hunt group to access the voice messaging system.
In addition to handling calls received by the PBX from incoming telephone trunks and direct internal calls, an important function of known voice messaging systems is the handling of calls which do not successfully reach the originally intended extension either because the extension was busy, did not answer, or had intentionally been placed in a mode in which it was not accepting calls. Such a function may be accomplished in known voice messaging systems by instructing the PBX to forward all such unanswered calls to a group of extensions coupled with the voice ports of the voice messaging system. As is know in the prior art, for example U.S. Pat. No. 4,926,462, voice message systems are also connected to the PBX in such a way as to receive information about the originally called extension number so that the voice message system can answer the call with the greeting of the called party and take a voice message that goes into the voice mailbox for that called person.
Another mechanism which has been used for the transmission and receipt of text messages involves computers. With the advent of personal computers and workstations, computing power was distributed to users at the desktop level. As is well know in the prior art, these personal computers (PCs) and workstations can be connected using Local Area Network (LAN) and Wide Area Network (WAN) hardware and software technology.
The interconnection of PCs and workstations into networks is becoming increasingly popular and one of the most common applications is that of electronic mail (E-mail). E-mail allows users to compose, send, and receive messages on their PCs or workstations over a LAN or WAN. Originally, E-mail systems only handled text-based messages. Increasingly, they are being enhanced to also support the transmission of other formats of information, such as graphics, spread sheets, facsimile, and voice.
Most of the E-mail systems available for PC network environments require a file server computer on the LAN. The most popular file server LAN software system is sold by Novell.TM. (Netware.TM.) or Microsoft.TM. (LAN Manager.TM.). These software systems allow programs on individual PCs to access files on a computer running the file server software. These files can either be shared access or assigned to a particular individual. They also support what are called "peer-to-peer" communications protocols, which allow PCs to send and receive data to and from other PCs on the LAN.
The E-mail software running on a particular user's PC uses a file server on a LAN as the "post office" for the mail messages. As an example, there is a shared file on the server that is the "user directory". It has information such as each users' E-mail addresses and passwords. The file server is also where the messages are stored when they are waiting to be accessed by a user. The server also contains information for each user regarding how many messages they have, the date and time of creation of each message, who it is from, who else was copied, etc. This information is sometimes called a message header or "envelope" information. Also supported in these E-mail systems is the ability to send E-mail messages to other E-mail systems located on a different LAN (usually via a dedicated WAN connection or via dial-up modems). In these cases there is software running on one of the PCs on the LAN that handles the moving of messages and of all the message header information from one file server via the WAN to another file server. There is also software that keeps the directories of these different LAN based E-mail systems automatically updated.
As indicated previously, the E-mail systems also support the ability to attach other files that are stored on the server as part of the E-mail message. In some E-mail systems, the names of these attached files might also be part of the message header information. These E-mail systems typically have available Application Program Interfaces (APIs) which allow software programs to be written to use the E-mail directory, message handling, user access and security mechanisms of that particular E-mail system for facilitating the development of other applications. The two most common LAN based E-mail systems are Microsoft Mail.TM. and Lotus cc:Mail.TM.. Microsoft.TM. supports a set of APIs called Messaging Application Program Interface (MAPI) and Lotus.TM. supports, as do other software companies, APIs called Vendor Independent Messaging (VIM).
In prior art voice messaging systems, the methods for keeping track of user directories, message header information, and the messages themselves is unique to each manufacturer. Virtually all these methods are different from the methods the E-mail software systems use to perform the same functions for E-mail. This means that a business organization that has both E-mail and voice messaging must maintain two user directories, two mailboxes per user, and two wide area networking and directory update systems. This is both inconvenient for the users and more expensive to manage for the business.
Therefore, there exists a need in the prior art for an integrated voice and electronic messaging system. Such an integrated system would allow companies to maintain only one directory for all voice and E-mail users, maintain only one method of wide area networking both kinds of messages, and give the users only one mailbox to check and use for all types of messages (e.g., voice, fax, text, graphic, etc.).